Mysterious Substance In Brain Could Explain Why You're Always Sleepy

Most of us have suffered from a few nights of bad sleep, making
it difficult to stay awake during the day. But for a select group
of people, extreme daytime sleepiness cannot be remedied by
getting more shut-eye.

This group has what's called primary hypersomnia. It's a rare
condition in which patients are continuously tired, despite
sleeping, on average, nearly 11 hours a day, or up to 75 hours
per week.

Until now, the cause of hypersomnia was not known, but
researchers at Emory University think they've found a lead.
They've identified a mysterious chemical that acts like a
sedative in the brains of people who can't seem to stay awake.

In the human brain, a chemical
called gamma-amino butyric acid, or GABA,
works to calm us down when it binds to its receptor. But in
individuals with primary hypersomia, researchers believe this
mystery substance in the cerebrospinal fluid (a
clear fluid that "bathes" the brain and spinal cord) binds to the
receptor and "changes its biophysical properties so that it
becomes more sensitive to GABA when it sees
GABA," lead author David Rye, a professor of neurology
at Emory University School of Medicine, explained to us in an
email.

People who suffer from hypersominsia say they "take a
coma," rather than a nap, Rye tells us. That's because naps are
generally refreshing. These people take long, deep
nighttime and daytime sleeps that are not
refreshing.

"They typically resort to elaborate means to
get themselves to wake-up — for example, multiple alarm clocks —
some that fly, some that walk and that need to be physically
'caught' in order to turn them off," Rye wrote.

Studying sleep

For the study, researchers gave seven hyper-sleepy patients
a drug called flumazenil, which is typically used to treat people
who overdose on sleep-inducing medications like Valium or Ambien.
The treatment improved reaction times and alertness in some
patients. This suggested there was some kind of substance
mimicking the effects of sleeping pills in hypersomnia patients,
though researchers are still not sure what that substance
is.